1. Field of the Invention
The present invention relates to the technical field of touch panels and, more particularly, to an active one-layer multi-touch sensor panel device.
2. Description of Related Art
Modern consumer electronics are mostly provided with a touchpad in a touch panel as one of the input devices. The principle of touch panels is based on different sensing manners to detect a voltage, current, acoustic wave, or infrared to detect the coordinate of a touch point on a screen where a finger or the like touches. For example, a capacitive touch panel uses a capacitance change generated in an electrostatic combination of the arranged transparent electrodes and a human body to generate a current or voltage for detecting the touching coordinates.
The need of multi-touch technology is increased as smart phones become more and more popular. Currently, the multi-touch technology essentially uses an Indium Tin Oxide (ITO) material to form a plurality of sensing units arranged in a matrix form with interlaced rows and columns, so as to detect accurate touch positions. The principle of the multi-touch technology is based on a capacitive sensing to use the design of a plurality ITO electrodes after etching to provide multiple sets of transparent conductive lines that are mutually vertical in different planes, so as to form driving lines of X-axis and Y-axis. These conductive lines are controlled by a controller to sequentially scan and detect the changes of capacitance for being fed to the controller.
However, the ITO material is very expensive, and thus a touch panel with a two-layer ITO material is gradually replaced by one with a one-layer ITO material.
FIG. 1 is a schematic view of a typical one-layer multi-touch sensor panel device. In FIG. 1, a plurality of ITO conductive lines are etched and formed on the one-layer multi-touch sensor panel device 110. The ITO conductive lines are divided into driving conductive lines 111 and sensing conductive lines 113. The driving conductive lines 111 and the sensing conductive lines 113 are in an interlaced arrangement without crossing to one another, so as to form a sensing block. As shown in FIG. 1, one driving conductive line 111 is operated with four sensing conductive lines 113 which are individually routed on the one-layer multi-touch sensor panel device 110 and connected to a flexible printed circuit board (FPC) 120. At last, the four sensing conductive lines 113 are short-circuited to form a line RX1 on the FPC 120, and the line RX1 is connected to the touch controller IC 121. Such a short-circuit line is advantageous in having no crossing line on the one-layer multi-touch sensor panel device 110, so that the one-layer multi-touch sensor panel device 110 can be implemented by one layer of conductor. Although the FPC 120 requires a larger area, the overall cost of the one-layer multi-touch sensor panel device is lower than that of the two-layer multi-touch sensor panel device.
The one-layer multi-touch sensor panel device in FIG. 1 can provide a benefit of low cost, but it has a disadvantage in being very sensitive to noises when performing touch and sensing. When the touch controller IC 121 drives the driving conductive line 111 during a certain time interval and a position C11 is touched by a finger, the touch controller IC 121 can detect the touch on the position C11. However, in the configuration of FIG. 1, if a noise presents at a position C31, due to the sensing conductive lines 113 on the positions C31 and C11 being short-circuited to form a line RX1 on the FPC 120, the sensed electrical feature at the position C11 is thus influenced, resulting in erroneous determination of the touch controller IC 121 and decreased accuracy of touch detection.
Therefore, it is desirable to provide an improved on-layer multi-touch sensor panel device to mitigate and/or obviate the aforementioned problems.